Changes in Some Carbohydrate Fractions and Some Related Enzymic Activities in Plump and Shrivelled Triticale and in Wheat Grains

Abstract

Activities of α-amylase (EC 3.2.1.1), β-amylase (EC 3.2.1.2), soluble ADPglucose-starch synthase (EC 2.4.1.21), starch phosphorylase (EC 2.4.1.1), sucrose synthase (EC 2.4.1.13) and invertase (EC 3.2.1.26), and amounts of reducing sugars, total soluble sugars and starch, were studied in the developing grains of wheat and triticale lines. A triticale line (TL1) with shrivelled grains contained a low starch content, increased reducing and total soluble sugars during the final grain-filling period as well as a higher moisture at maturity than wheat and a plump-grain triticale line (TL2). The overall activities of soluble ADPglucose-starch synthase and starch phosphorylase remained lower and that of α- and β-amylases higher in TL1 than wheat and TL2 throughout grain development. The higher amylolytic activity retained during the final maturation period appears to be at least partly due to the higher moisture content of the grain in the triticale line TL1 with shrivelled grains.